Power supplies for lighted shelves in a refrigerator

ABSTRACT

Illustrative embodiments of systems and methods for powering lighted shelves in refrigerator appliances are included. In one embodiment, a refrigerator appliance may comprise a cabinet having a temperature-controlled compartment defined therein, a shelf ladder disposed at least partially in the temperature-controlled compartment and providing a plurality of shelf mounting positions, the shelf ladder comprising an electrical bus including first, second, and third conductors, the second conductor configured to supply power at a first current level when electrically coupled to the first conductor, the third conductor configured to supply power at a second current level when electrically coupled to the first conductor, and a first adjustable shelf carrying a first lighting device, the first adjustable shelf being removably mountable in one of the plurality of shelf mounting positions such that the first lighting device is electrically coupled between the first conductor and the second conductor.

TECHNICAL FIELD

The present disclosure relates, generally, to refrigerator appliancesand, more particularly, to systems and methods for powering lightedshelves in refrigerator appliances.

BACKGROUND

A refrigerator is an appliance used to store food items at presettemperatures. A refrigerator appliance typically includes one or moretemperature-controlled compartments into which food items may be placedto preserve the food items for later consumption. A refrigeratorappliance also typically includes a plurality of shelves on which thefood items may be arranged within the one or more temperature-controlledcompartments. In some refrigerator appliances, the plurality of shelvesmay be adjustable (i.e., the shelves may each be removably mounted in aplurality of shelf mounting positions). Some or all of the plurality ofshelves may also carry one or more lighting devices for illuminatingfood items placed in the one or more temperature-controlledcompartments.

SUMMARY

According to one aspect, a refrigerator appliance may comprise a cabinethaving a temperature-controlled compartment defined therein, a shelfladder disposed at least partially in the temperature-controlledcompartment and providing a plurality of shelf mounting positions, theshelf ladder comprising an electrical bus including first, second, andthird conductors, the second conductor configured to supply power at afirst current level when electrically coupled to the first conductor,the third conductor configured to supply power at a second current levelwhen electrically coupled to the first conductor, and a first adjustableshelf carrying a first lighting device, the first adjustable shelf beingremovably mountable in one of the plurality of shelf mounting positionssuch that the first lighting device is electrically coupled between thefirst conductor and the second conductor.

In some embodiments, the refrigerator appliance may further comprise asecond adjustable shelf carrying a second lighting device, the secondadjustable shelf being removably mountable in one of the plurality ofshelf mounting positions such that the second lighting device iselectrically coupled between the first conductor and the thirdconductor. In other embodiments, the first adjustable shelf may furthercomprise a second lighting device, the second lighting device beingelectrically coupled between the first conductor and the third conductorwhen the first adjustable shelf is removably mounted in one of theplurality of shelf mounting positions. The first conductor may bepositioned between the second and third conductors and may be spacedapart from both the second and third conductors. The first conductor maybe electrically grounded.

In still other embodiments, the first adjustable shelf may comprise amounting bracket configured to engage the shelf ladder to cantilever thefirst adjustable shelf in one of the plurality of shelf mountingpositions. In such embodiments, the mounting bracket may comprise afirst tab configured to electrically couple to the first conductor andto the second conductor when the first adjustable shelf is cantileveredin one of the plurality of shelf mounting positions. The mountingbracket may further comprise a second tab configured to electricallycouple to the first conductor and to the third conductor when the firstadjustable shelf is cantilevered in one of the plurality of shelfmounting positions. The first and second tabs of the mounting bracketmay each be electrically isolated from a body of the mounting bracketthat supports the first adjustable shelf.

In some embodiments, at least one of the first and second conductors maybe spring-loaded to apply force against the first tab when the firstadjustable shelf is cantilevered in one of the plurality of shelfmounting positions. In such embodiments, the first tab may be configuredto scrape a portion of the first conductor and a portion of the secondconductor as the first adjustable shelf is cantilevered in one of theplurality of shelf mounting positions.

According to another aspect, a refrigerator appliance may comprise acabinet having a temperature-controlled compartment defined therein, afirst shelf ladder disposed at least partially in thetemperature-controlled compartment and including a first electrical busconfigured to supply power at a first current level, a second shelfladder disposed at least partially in the temperature-controlledcompartment and including a second electrical bus configured to supplypower at a second current level, and a first adjustable shelf carrying afirst lighting device, the first adjustable shelf being removablymountable on the first and second shelf ladders such that the firstlighting device is electrically coupled to the first electrical bus.

In some embodiments, the refrigerator appliance may further comprise asecond adjustable shelf carrying a second lighting device, the secondadjustable shelf being removably mountable on the first and second shelfladders such that the second lighting device is electrically coupled tothe second electrical bus. In other embodiments, the first adjustableshelf may further comprise a second lighting device, the second lightingdevice being electrically coupled to the second electrical bus when thefirst adjustable shelf is removably mounted in one of the plurality ofshelf mounting positions.

In still other embodiments, the first adjustable shelf may comprise afirst mounting bracket configured to engage the first shelf ladder and asecond mounting bracket configured to engage the second shelf ladder tocantilever the first adjustable shelf on the first and second shelfladders. In such embodiments, the first mounting bracket may comprise afirst tab configured to electrically couple to the first electrical buswhen the first adjustable shelf is cantilevered on the first and secondshelf ladders. The second mounting bracket may comprise a second tabconfigured to electrically couple to the second electrical bus when thefirst adjustable shelf is cantilevered on the first and second shelfladders. The first tab of the first mounting bracket may be electricallyisolated from a body of the first mounting bracket that supports thefirst adjustable shelf.

In some embodiments, the first electrical bus may comprise first andsecond conductors having a gap therebetween, the gap between the firstand second conductors being sized to receive the first tab when thefirst adjustable shelf is cantilevered on the first and second shelfladders. At least one of the first and second conductors may bespring-loaded to apply force against the first tab when the firstadjustable shelf is cantilevered on the first and second shelf ladders.In such embodiments, the first tab may be configured to scrape a portionof the first conductor and a portion of the second conductor as thefirst adjustable shelf is cantilevered on the first and second shelfladders.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the following figures,in which:

FIG. 1 is a front elevation view of a refrigerator appliance showing anumber of adjustable shelves removably mounted in a plurality of shelfmounting positions within a temperature-controlled compartment of therefrigerator appliance;

FIG. 2A is top plan view of one embodiment of an adjustable shelf thatis removably mountable in the refrigerator appliance of FIG. 1;

FIG. 2B is a cross-sectional view of the adjustable shelf of FIG. 2A,taken along the line 2B 2B in FIG. 2A;

FIG. 3 is a partially exploded view of one embodiment of a shelf ladder,an electrical bus, and a mounting bracket of the refrigerator applianceof FIG. 1;

FIG. 4A is a front elevation view of the shelf ladder and the electricalbus of FIG. 3;

FIG. 4B is a top cross-sectional view of one embodiment of a mountingbracket engaging the shelf ladder and the electrical bus of FIG. 4A;

FIG. 5A is a front elevation view of another embodiment of a shelfladder and an electrical bus of the refrigerator appliance of FIG. 1;and

FIG. 5B is a top cross-sectional view of one embodiment of a mountingbracket engaging the shelf ladder and the electrical bus of FIG. 5A.

Where considered appropriate, reference labels have been repeated amongthe figures to indicate corresponding or analogous elements.

DETAILED DESCRIPTION OF THE DRAWINGS

While the concepts of the present disclosure are susceptible to variousmodifications and alternative forms, specific exemplary embodimentsthereof have been shown by way of example in the drawings and willherein be described in detail. It should be understood, however, thatthere is no intent to limit the concepts of the present disclosure tothe particular forms disclosed, but on the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

Referring to FIG. 1, a home appliance is shown as a refrigeratorappliance 100 (hereinafter, the refrigerator 100). One illustrativeexample of the refrigerator 100 is the Whirlpool Latitude French DoorRefrigerator, which is commercially available from Whirlpool Corporationof Benton Harbor, Mich. The refrigerator 100 includes a lower frame 102and a cabinet 104 extending upwardly from the lower frame 102. Thecabinet 104 of the refrigerator 100 includes a pair oftemperature-controlled compartments 106 that are independently operableto maintain food items stored therein at one or more set temperatures.

The lower temperature-controlled compartment 106 is a freezercompartment 106A, and the refrigerator 100 includes a drawer 108 that ispositioned in the freezer compartment 106A. The drawer 108 is moveablerelative to the cabinet 104 such that food items may be placed in thedrawer 108 for storage in the freezer compartment 106A and retrievedfrom the drawer 108 when ready for use. A handle 110 is located on thedrawer 108 so that a user may open and close the drawer 108.

The upper temperature-controlled compartment 106 is a refrigeratedcompartment 106B into which a user may place and store food items suchas milk, cheese, produce, etcetera. A pair of doors 112 are each hingedto the front of the cabinet 104 via a pair of hinge assemblies 114. Thedoors 112 permit user access to the refrigerated compartment 106B suchthat food items may be placed in and retrieved from the refrigeratedcompartment 106B. A handle 116 is located on each of the doors 112 sothat a user may open and close the doors 112.

While the illustrative embodiment of the refrigerator 100 shown in FIG.1 is a “french-door” model with a pair of doors 112 operable to permitaccess to the refrigerated compartment 106B, it should be appreciatedthat other configurations are contemplated, such as, for example,configurations having only one door 112 operable to permit access to therefrigerated compartment 106B. Additionally, it should also beappreciated that, in some embodiments, the freezer compartment 106A maybe positioned above the refrigerated compartment 106B and, in otherembodiments, either one of the temperature-controlled compartments 106may be omitted. It should be further appreciated that, in someembodiments, the refrigerator 100 may include more than one freezercompartment 106A and/or more than one refrigerated compartment 106B.Configurations of the refrigerator 100 are also contemplated in whichthe freezer compartment 106A is located on one side of the cabinet 104and the refrigerated compartment 106B is located on the opposite side ofthe cabinet 104.

As shown in FIG. 1, the refrigerator 100 also includes four adjustableshelves 120 removably mounted within the refrigerated compartment 106B,upon which a user of the refrigerator 100 may arrange food items. It iscontemplated that the refrigerator 100 may include any number ofadjustable shelves 120 within the temperature-controlled compartments106. As the adjustable shelves 120 are removably mounted within therefrigerated compartment 106B, a user may remove any adjustable shelf120 and relocate it to any available shelf mounting position within therefrigerated compartment 106B. It will be appreciated that therefrigerator 100 may additionally or alternatively include other devicesfor supporting or storing food within the temperature-controlledcompartments 106, such as, for example, drawers 122 or door bins 124 (asshown in FIG. 1). As used in the present disclosure, the term “shelf” isto be considered in its broadest sense as any device that will hold afood item, including shelves, drawers, bins, panels, racks, and thelike.

The adjustable shelves 120 may be removably mounted within therefrigerated compartment 106B using any suitable mechanism. In theillustrative embodiment of the refrigerator 100 shown in FIG. 1, threeshelf ladders 126 are disposed within the refrigerated compartment 106Bto provide a plurality of shelf mounting positions for the adjustableshelves 120. It is contemplated that any number of shelf ladders 126 maybe used for removably mounting the adjustable shelves 120. In someembodiments, the shelf ladders 126 may be secured to one or more wallsof the refrigerator compartment 106B using screws, bolts, rivets,adhesive, or other fixation mechanisms. In other embodiments, the shelfladders 126 may be integrally formed into one or more walls of therefrigerator compartment 106B. It should also be appreciated that theadjustable shelves 120 may be removably mounted within the refrigeratedcompartment 106B using any number of mechanisms other than the shelfladders 126. By way of example, the adjustable shelves 120 may beremovably mounted within the refrigerated compartment 106B using ledges,tracks, slides, glides, rollers, and the like.

One illustrative embodiment of an adjustable shelf 120 that is removablymountable within the refrigerated compartment 106B is shown in FIGS. 2Aand 2B. The adjustable shelf 120 includes a support surface 200 uponwhich a user of the refrigerator 100 may arrange food items. The supportsurface 200 may illustratively be formed of glass, plastic, or any othersuitable material. As shown in FIGS. 2A and 2B, the support surface 200is illustratively bounded on three sides by lips 202, which assist inretaining food items arranged on the support surface 200 of theadjustable shelf 120.

In the illustrative embodiment, the adjustable shelf 120 includes a pairof mounting brackets 204 that are spaced apart from one another the samedistance as a pair of the shelf ladders 126 of the refrigerator 100. Asdescribed further below (with reference to FIG. 3), these mountingbrackets 204 allow the adjustable shelf 120 to be removably mounted on apair of the shelf ladders 126. As illustrated in FIG. 2B, each of themounting brackets 204 of the adjustable shelf 120 may include a body anda number of tabs 206 configured to engage a number of slots of one ofthe shelf ladders 126. In some embodiments, the mounting bracket 204 mayinclude multiple upper tabs 206 and/or multiple lower tabs 206 extendingfrom the body of the mounting bracket 204. Any of the tabs 206 of themounting bracket 204 may include a conductor 208 disposed on orintegrated into the tab 206. Where one of the tabs 206 includes aconductor 208, the tab 206 may be electrically isolated from the body ofthe mounting bracket 204 (particularly, where the mounting bracket 204is formed of a conductive material, such as steel).

Some or all of the adjustable shelves 120 may carry one or more lightingdevices 210 for illuminating food items placed in the refrigeratedcompartment 106B. For instance, each of the adjustable shelves 120 maycarry one or more light emitting diodes (LEDs) 210. It is contemplatedthat, in some embodiments, some of the adjustable shelves 120 of therefrigerator 100 may not carry a lighting device (i.e., the refrigerator100 may include both lighted and non-lighted adjustable shelves 120).Each lighting device 210 carried by an adjustable shelf 120 may beelectrically coupled to a conductor 208 disposed on or integrated intoone of the tabs 206 of a mounting bracket 204 of the adjustable shelf120. As described further below, the conductor 208 may be electricallycoupled to an electrical bus in one of the shelf ladders 126 when theadjustable shelf is removably mounted in the refrigerated compartment106B. As such, the corresponding lighting device 210 will also beelectrically coupled to the electrical bus in the shelf ladder 126 whenthe adjustable shelf is removably mounted in the refrigeratedcompartment 106B.

As shown in more detail in FIG. 3, each of the shelf ladders 126 in theillustrative embodiment of refrigerator 100 has a number of slots 300defined therein. As described above, each of the adjustable shelves 120may illustratively include a pair of mounting brackets 204 that arespaced apart from one another the same distance as a pair of the shelfladders 126 (one such mounting bracket 204 being shown in FIG. 3). Themounting brackets 204 of an adjustable shelf 120 may each engage one ormore slots 300 defined in one of the shelf ladders 126 to cantilever theadjustable shelf 120 to a pair of shelf ladders 126. As such, the slots300 defined in the shelf ladders 126 provide a plurality of shelfmounting positions for the adjustable shelves 120. In the illustrativeembodiment, the slots 300 defined in the shelf ladders 126 (and, hence,the shelf mounting positions) are spaced approximately one inch apart.It will be appreciated that other configurations for the spacing of theslots 300 and the shelf mounting positions are possible.

In the illustrative embodiment of the refrigerator 100, one or more ofthe shelf ladders 126 may include an electrical bus 302 positionedwithin (or behind) each slot 300 defined in the shelf ladder(s) 126, asillustrated in FIG. 3. It will be appreciated that, where eachadjustable shelf 120 engages two or more shelf ladders 126, only some ofthe shelf ladders 126 may include an electrical bus 302. The electricalbus 302 includes an insulating housing 304 that supports at least oneelectrical conductor 306. In some embodiments, the insulating housing304 may include a number of protrusions 308 that snap into correspondingholes 310 on the shelf ladder 126 to secure the electrical bus 302behind the shelf ladder 126. In other embodiments, an electrical bus 302may be secured to one of the shelf ladders 126 using screws, bolts,rivets, adhesive, or other fixation mechanisms.

As described above (with reference to FIG. 2B), a mounting bracket 204of an adjustable shelf 120 may include a number of tabs 206 configuredto engage a number of slots 300 of one of the shelf ladders 126. In theillustrative embodiment of FIG. 3, an upper tab 206 may have a hookshape that rests on a lower edge of one of the slots 300 when theadjustable shelf 120 is removably mounted in one of the shelf mountingpositions. The mounting bracket 204 may also have a lower tab 206 thatextends through an adjacent slot 300 of the shelf ladder 126. As notedabove, the mounting bracket 204 may include multiple upper tabs 206and/or multiple lower tabs 206 extending from the body of the mountingbracket 204, any of which may include one or more conductors 208. Whenone of the tabs 206 extends through a slot 300 defined in the shelfladder 126 (when the adjustable shelf 120 is removably mounted in one ofthe shelf mounting positions), a conductor 208 carried by the tab 206may contact the at least one conductor 306 of the electrical bus 302behind the slot 300 to provide power to any lighting devices 210 carriedby the adjustable shelf 120. It is contemplated that each mountingbracket 204 (and each tab 206 thereof) may carry any number ofconductors 208 for interfacing with any number of conductors 306included in the electrical bus 302.

As shown in the illustrative embodiment of FIGS. 4A and 4B, theelectrical bus 302 may include two conductors 306, 400 supported behindthe shelf ladder 126. Both of the conductors 306, 400 are accessiblethrough one or more of the slots 300 of the shelf ladder 126, but areotherwise shielded by a face of the shelf ladder 126. As illustrated bythe conductor 306 in FIG. 4A, some or all of the conductors of theelectrical bus 302 may be continuous and may be exposed in each slot 300of the shelf ladder 126. Additionally or alternatively, as illustratedby the conductor 400 in FIG. 4A, some or all of the conductors of theelectrical bus 302 may be separated into discrete sections 400A, 400Bthat are each exposed in only some slots 300 of the shelf ladder 126.These discrete sections 400A, 400B of the conductor 400 may each formindependent electrical circuits with the continuous conductor 306. Inthe illustrative embodiment of FIGS. 4A and 4B, the continuous conductor306 is electrically grounded.

The engagement of a mounting bracket 204 of an adjustable shelf 120 withthe shelf ladder 126 and the electrical bus 302 of FIG. 4A isillustratively shown in cross-section in FIG. 4B. The conductors 306,400 of the electrical bus 302 are each disposed on one side of thehousing 304 and are spaced apart by a gap 402. The gap 402 may be sizedto prevent degenerate growth between the conductors 306, 400. One orboth of the conductors 306, 400 may be spring-loaded to narrow (but notclose) the gap 402 between the conductors 306, 400. In the illustrativeembodiment of FIG. 4B, the conductors 306, 400 are each comprised of adeformable metal that may be bent out of shape by sufficient force, butthat returns to its original shape in the absence of such force. It isalso contemplated that, in other embodiments, the conductors 306, 400may be spring-loaded by other mechanisms (e.g., non-deformableconductors 306, 400 that are coupled to the housing 304 by traditionalsprings).

Where the conductors 306, 400 are spring-loaded, the conductors 306, 400will apply force against a tab 206 of the mounting bracket 204 that isreceived in the slot 300 of the shelf ladder 126. This force between theconductors 306, 400 and the tab 206 may help to ensure a good electricalconnection between the conductors 306, 400 and a conductor 208 carriedby the tab 206. Furthermore, where the conductors 306, 400 arespring-loaded, the tab 206 may scrape portions of the conductors 306,400 as the tab 206 enters the electrical bus 302 and pushes against theconductors 306, 400. This scraping may remove surface grime from theconductors 306, 400 and further help to ensure a good electricalconnection between the conductors 306, 400 and a conductor 208 carriedby the tab 206.

As described above, in one illustrative embodiment of the refrigerator100, each adjustable shelf 120 includes two mounting brackets 204 thateach engage one of the shelf ladders 126. In embodiments where eachshelf ladder 126 includes an associated electrical bus 302, one or morelighting devices 210 carried by each adjustable shelf 120 mayelectrically couple to one or both electrical buses 302. The lightingdevices 210 may electrically couple to the electrical buses 302 via oneor more conductors 208 carried by one or more tabs 206 of one or bothmounting brackets 204. For instance, one adjustable shelf 120 mayelectrically couple its lighting device 210 to the electrical bus 302 ofa first shelf ladder 126, while another adjustable shelf 120 mayelectrically couple its lighting device 210 to the electrical bus 302 ofa second shelf ladder 126 (both adjustable shelves 120 beingcantilevered on the first and second shelf ladders 126). Additionally oralternatively, an adjustable shelf 120 may electrically couple a firstlighting device 210 to the electrical bus 302 of a first shelf ladder126, while electrically coupling a second lighting device 210 carried bythe same adjustable shelf 120 to the electrical bus 302 of a secondshelf ladder 126.

Where each adjustable shelf 120 is removably mountable on two shelfladders 126, each including a corresponding electrical bus 302, thesetwo electrical buses 302 may supply power at different current levels.For instance, one electrical bus may supply power at a current level of100 milliamps, while the other electrical bus 302 supplies power at alower current level, such as, for example, 30 or 50 milliamps. Where twoelectrical buses 302 are available to supply power to each adjustableshelf 120 at different current levels (e.g., 30, 50, or 100 milliamps),the adjustable shelves 120 may carry different types of LEDs 210. Forinstance, some adjustable shelves 120 may carry white LEDs 210, otheradjustable shelves 120 may carry color LEDs 210, and still otheradjustable shelves 120 may carry both white and color LEDs 210. Eachadjustable shelf 120 may then electrically couple each of the LEDs 210to the appropriate electrical bus 302 to receive power at theappropriate current level for that LED 210.

As shown in FIGS. 5A and 5B, another illustrative embodiment of theelectrical bus 302 may include three conductors 306, 400, 500 supportedbehind the shelf ladder 126. Each of the conductors 306, 400, 500 isaccessible through one or more of the slots 300 of the shelf ladder 126,but is otherwise shielded by a face of the shelf ladder 126. Asillustrated by the conductor 306 in FIG. 5A, some or all of theconductors of the electrical bus 302 may be continuous and may beexposed in each slot 300 of the shelf ladder 126. Additionally oralternatively, as illustrated by the conductors 400, 500 in FIG. 5A,some or all of the conductors of the electrical bus 302 may be separatedinto discrete sections 400A, 400B, 500A, 500B that are each exposed inonly some slots 300 of the shelf ladder 126. These discrete sections400A, 400B, 500A, 500B of the conductors 400, 500 may each formindependent electrical circuits with the continuous conductor 306. Inthe illustrative embodiment of FIGS. 5A and 5B, the continuous conductor306 is electrically grounded.

The engagement of a mounting bracket 204 of an adjustable shelf 120 withthe shelf ladder 126 and the electrical bus 302 of FIG. 5A isillustratively shown in cross-section in FIG. 5B. The conductors 400,500 of the electrical bus 302 are each disposed on one side of thehousing 304. The conductor 306 is disposed between the conductors 400,500 and is spaced apart from each conductor 400, 500 by a respective gap402. The respective gaps 402 may be sized to prevent degenerate growthbetween the conductors 306, 400, 500. One or more of the conductors 306,400, 500 may be spring-loaded to narrow (but not close) the gaps 402between the conductors 306, 400, 500. In the illustrative embodiment ofFIG. 5B, the conductors 306, 400, 500 are each comprised of a deformablemetal that may be bent out of shape by sufficient force, but thatreturns to its original shape in the absence of such force. It is alsocontemplated that, in other embodiments, the conductors 306, 400, 500may be spring-loaded by other mechanisms (e.g., non-deformableconductors 400, 500 that are coupled to the housing 304 by traditionalsprings).

Where the conductors 306, 400, 500 are spring-loaded, the conductors306, 400, 500 will apply force against the tabs 206 of the mountingbracket 204 that are received in the slot 300 of the shelf ladder 126.This force between the conductors 306, 400, 500 and the tabs 206 mayhelp to ensure a good electrical connection between the conductors 306,400, 500 and one or more conductors 208 carried by the tabs 206.Furthermore, where the conductors 306, 400, 500 are spring-loaded, thetabs 206 may scrape portions of the conductors 306, 400, 500 as the tabs206 enter the electrical bus 302 and push against the conductors 306,400, 500. This scraping may remove surface grime from the conductors306, 400, 500 and further help to ensure a good electrical connectionbetween the conductors 306, 400, 500 and one or more conductors 208carried by the tabs 206.

In an illustrative embodiment of the refrigerator 100 employing theshelf ladder 126 and electrical bus 302 of FIGS. 5A and 5B, one or morelighting devices 210 carried by each adjustable shelf 120 mayelectrically couple to either the conductors 306, 400 or the conductors306, 500. The lighting devices 210 may electrically couple to eitherpair of conductors of the electrical bus 302 via one or more conductors208 carried by one or more tabs 206 of a mounting bracket 204 of theadjustable shelf 120. For instance, one adjustable shelf 120 mayelectrically couple its lighting device 210 to the conductors 306, 400of the electrical bus 302, while another adjustable shelf 120 mayelectrically couple its lighting device 210 to the conductors 306, 500of the electrical bus 302. Additionally or alternatively, an adjustableshelf 120 may electrically couple a first lighting device 210 to theconductors 306, 400 of the electrical bus 302, while electricallycoupling a second lighting device 210 carried by the same adjustableshelf 120 to the conductors 306, 500 of the electrical bus 302.

In embodiments employing the electrical bus 302 of FIGS. 5A and 5B, theconductors 400, 500 may supply power at different current levels whenelectrically coupled to the conductor 306. For instance, the conductor400 may supply power at a current level of 100 milliamps, while theconductor 500 may supply power at a lower current level, such as, forexample, 30 or 50 milliamps. Where different pairs of the conductors306, 400, 500 are available to supply power to each adjustable shelf 120at different current levels (e.g., 30, 50, or 100 milliamps), theadjustable shelves 120 may carry different types of LEDs 210. Forinstance, some adjustable shelves 120 may carry white LEDs 210, otheradjustable shelves 120 may carry color LEDs 210, and still otheradjustable shelves 120 may carry both white and color LEDs 210. Eachadjustable shelf 120 may then electrically couple each of the LEDs 210to the appropriate pair of the conductors 306, 400, 500 of theelectrical bus 302 to receive power at the appropriate current level forthat LED 210.

There are a plurality of advantages of the present disclosure arisingfrom the various features of the systems, apparatus, and methodsdescribed herein. It will be noted that alternative embodiments of thesystems, apparatus, and methods of the present disclosure may notinclude all of the features described yet still benefit from at leastsome of the advantages of such features. Those of ordinary skill in theart may readily devise their own implementations of the systems,apparatus, and methods that incorporate one or more of the features ofthe present disclosure and fall within the spirit and scope of thepresent invention as defined by the appended claims.

The invention claimed is:
 1. A refrigerator appliance comprising: acabinet having a temperature-controlled compartment defined therein; ashelf ladder disposed at least partially in the temperature-controlledcompartment and providing a plurality of shelf mounting positions, theshelf ladder comprising an electrical bus including first, second, andthird bus conductors, the second bus conductor connected to a firstcircuit that supplies power at a first current level when electricallycoupled to the first bus conductor, the third bus conductor connected toa second circuit that supplies power at a second current level whenelectrically coupled to the first bus conductor; and a first adjustableshelf carrying a first lighting device, the first adjustable shelf beingremovably mountable in one of the plurality of shelf mounting positionssuch that the first lighting device is electrically coupled between thefirst bus conductor and the second bus conductor.
 2. The refrigeratorappliance of claim 1, further comprising a second adjustable shelfcarrying a second lighting device, the second adjustable shelf beingremovably mountable in one of the plurality of shelf mounting positionssuch that the second lighting device is electrically coupled between thefirst bus conductor and the third bus conductor.
 3. The refrigeratorappliance of claim 1, wherein the first adjustable shelf furthercomprises a second lighting device, the second lighting device beingelectrically coupled between the first bus conductor and the third busconductor when the first adjustable shelf is removably mounted in one ofthe plurality of shelf mounting positions.
 4. The refrigerator applianceof claim 1, wherein the first bus conductor is positioned between thesecond and third bus conductors and is spaced apart from both the secondand third bus conductors.
 5. The refrigerator appliance of claim 4,wherein the first bus conductor is electrically grounded.
 6. Therefrigerator appliance of claim 1, wherein the first adjustable shelfcomprises a mounting bracket configured to engage the shelf ladder tocantilever the first adjustable shelf in one of the plurality of shelfmounting positions, the mounting bracket comprising a first tabconfigured with tab electrical conductors in electrical communicationwith the first lighting device to electrically couple to the first busconductor and to the second bus conductor when the first adjustableshelf is cantilevered in one of the plurality of shelf mountingpositions.
 7. The refrigerator appliance of claim 6, wherein themounting bracket further comprises a second tab configured with tabelectrical conductors to electrically couple to the first bus conductorand to the third bus conductor when the first adjustable shelf iscantilevered in one of the plurality of shelf mounting positions.
 8. Therefrigerator appliance of claim 7, wherein the tab electrical conductorsof the first and second tabs of the mounting bracket are eachelectrically isolated from a body of the mounting bracket that supportsthe first adjustable shelf.
 9. The refrigerator appliance of claim 6,wherein at least one of the first and second bus conductors isspring-loaded to apply force against a tab conductor of the first tabwhen the first adjustable shelf is cantilevered in one of the pluralityof shelf mounting positions.
 10. The refrigerator appliance of claim 9,wherein tab conductors of the first tab is configured to scrape aportion of the first bus conductor and a portion of the second busconductor as the first adjustable shelf is cantilevered in one of theplurality of shelf mounting positions.
 11. A refrigerator appliancecomprising: a cabinet having a temperature-controlled compartmentdefined therein; a first shelf ladder disposed at least partially in thetemperature-controlled compartment and including a first electrical busconnected to a first circuit that supplies power at a first currentlevel; a second shelf ladder disposed at least partially in thetemperature-controlled compartment and including a second electrical busconnected to a second circuit that supplies power at a second currentlevel; and a first adjustable shelf carrying a first lighting device,the first adjustable shelf being removably mountable on the first andsecond shelf ladders such that the first lighting device is electricallycoupled to the first electrical bus.
 12. The refrigerator appliance ofclaim 11, further comprising a second adjustable shelf carrying a secondlighting device, the second adjustable shelf being removably mountableon the first and second shelf ladders such that the second lightingdevice is electrically coupled to the second electrical bus.
 13. Therefrigerator appliance of claim 11, wherein the first adjustable shelffurther comprises a second lighting device, the second lighting devicebeing electrically coupled to the second electrical bus when the firstadjustable shelf is removably mounted in one of the plurality of shelfmounting positions.
 14. The refrigerator appliance of claim 11, whereinthe first adjustable shelf comprises a first mounting bracket configuredto engage the first shelf ladder and a second mounting bracketconfigured to engage the second shelf ladder to cantilever the firstadjustable shelf on the first and second shelf ladders.
 15. Therefrigerator appliance of claim 14, wherein the first mounting bracketcomprises a first tab configured to electrically couple to the firstelectrical bus when the first adjustable shelf is cantilevered on thefirst and second shelf ladders.
 16. The refrigerator appliance of claim15, wherein the second mounting bracket comprises a second tabconfigured to electrically couple to the second electrical bus when thefirst adjustable shelf is cantilevered on the first and second shelfladders.
 17. The refrigerator appliance of claim 15, wherein the firsttab of the first mounting bracket is electrically isolated from a bodyof the first mounting bracket that supports the first adjustable shelf.18. The refrigerator appliance of claim 15, wherein the first electricalbus comprises first and second conductors having a gap therebetween, thegap between the first and second conductors being sized to receive thefirst tab when the first adjustable shelf is cantilevered on the firstand second shelf ladders.
 19. The refrigerator appliance of claim 18,wherein at least one of the first and second conductors is spring-loadedto apply force against the first tab when the first adjustable shelf iscantilevered on the first and second shelf ladders.
 20. The refrigeratorappliance of claim 19, wherein the first tab is configured to scrape aportion of the first conductor and a portion of the second conductor asthe first adjustable shelf is cantilevered on the first and second shelfladders.